Molecular and phenotypic characterization of enterococci isolated from broiler flocks in Turkey

  • Özkan AslantaşEmail author
Regular Articles


The aim of this study was to determine the antimicrobial resistance, resistance mechanisms implicated, and virulence genes (asa1, gelE, cylA, esp, and hyl) of Enterococcus spp. isolated from broiler flocks in Turkey. In addition, clonality of ampicillin and vancomycin-resistant enterococci was also investigated using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Out of 430 cloacal swab samples investigated, 336 (78.1%) Enterococcus spp. was isolated. The most frequently identified species were E. faecalis (87.8%), E. faecium (8.3%), E. durans (2.4%), E. casseliflavus (0.9%), and E. hirae (0.6%). The most common resistance was against tetracycline (81.3%), erythromycin (77.1%), ciprofloxacin (56.8%), and chloramphenicol (46.4%). Fifty (14.9%) isolates showed high-level gentamicin resistance (HLGL) phenotype. Ampicillin and vancomycin resistance were observed in 3.3% and 1.5% of the isolates, respectively. Two hundred eighty-three isolates were positive for the presence of virulence genes. Among the virulence genes tested, only gelE, asa1, esp, and cylA genes were detected. The most prevalent virulence gene was gelE (234, 69.6%), followed by asa1 (160, 47.6%), esp (37, 11%), and cylA (2, 0.6%). In conclusion, this study revealed that commensal enterococci from broiler flocks showed high rate of resistance to antimicrobials including clinically important antimicrobials for humans. The main underlying reason for high resistance could be attributed to the inappropriate and widespread use of antimicrobials. Therefore, there is an urgent need to develop control strategies to prevent the emergence and spread of antimicrobial resistance.


Antimicrobial resistance Broiler Enterococci Molecular characterization Virulence 


Funding information

This work was supported by the Hatay Mustafa Kemal University Scientific Research Fund under Grant number of 15660.

Compliance with ethical standards

This study was approved by the Animal Ethical Committee of Mustafa Kemal University with decision number of 2015-9/2. Written informed consent was obtained from the owners of the broiler farms.

Conflict of interest

The authors declare that they have no conflict of interest.


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© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Department of Microbiology, Faculty of Veterinary MedicineHatay Mustafa Kemal UniversityHatayTurkey

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